Next generation networks, including next generation wireless networks are expected to require clock synchronization between network elements within the network. Such network elements can include base stations, remote radio heads, Cloud Radio Access Network (C-RAN) data center baseband units (BBUs), and the like. Next generation of wireless networks are expected to utilize optical fibers to connect transceivers at antennas to transceivers at base stations or C-RAN BBUs.
Optical communication systems typically involve each optical fiber transmitting signals in a single direction. Accordingly two different optical fibers are used for two-way transmission between transceivers.
These network elements (also called nodes) have in the past been synchronized using synchronization based on a Global Navigation Satellite System (GNSS). Global Positioning Satellite (GPS) synchronization is one example. However, GPS/GNSS may not be available at indoor locations, or due to antenna access issues. Further, recently there have been security concerns regarding GPS synchronization. Furthermore GPS synchronization requires costly GPS receivers at each node. In a network of nodes using GPS synchronization, each node in the network receives signals from satellites, and in accordance with the received signals (and optionally in accordance with a known position), a time value can be obtained. The local clock at the node is then synchronized to this time. When each node in the network synchronizes in the same manner, they can each be considered to be synchronized with the GPS system, and thus sufficiently synchronized to each other. Use of an over-the-air channel for synchronization makes nodes subject to jamming of the synchronization signals which could result in a node going offline.
Accordingly, there is a need for a system and method that at least partially addresses one or more limitations of the prior art. In particular there is a need for a system and method for providing accurate clock synchronization for next generation wireless networks and other networks without relying on GPS synchronization.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.